#ifndef __REG_H__
#define __REG_H__

#include "common.h"

enum { R_EAX, R_ECX, R_EDX, R_EBX, R_ESP, R_EBP, R_ESI, R_EDI };
enum { R_AX, R_CX, R_DX, R_BX, R_SP, R_BP, R_SI, R_DI };
enum { R_AL, R_CL, R_DL, R_BL, R_AH, R_CH, R_DH, R_BH };

/* TODO: Re-organize the `CPU_state' structure to match the register
 * encoding scheme in i386 instruction format. For example, if we
 * access cpu.gpr[3]._16, we will get the `bx' register; if we access
 * cpu.gpr[1]._8[1], we will get the 'ch' register. Hint: Use `union'.
 * For more details about the register encoding scheme, see i386 manual.
 */

typedef struct {
	union {
		union {
			uint32_t _32;
			uint16_t _16;
			uint8_t _8[2];
		} gpr[8];

		/* Do NOT change the order of the GPRs' definitions. */
		struct {
			uint32_t eax, ecx, edx, ebx, esp, ebp, esi, edi;
		};
	};


     swaddr_t eip;

     union {
    struct {
        uint32_t CF     : 1;   // Carry Flag
        uint32_t        : 1;   // 保留位，未使用
        uint32_t PF     : 1;   // Parity Flag
        uint32_t        : 1;   // 保留位，未使用
        uint32_t AF     : 1;   // Auxiliary Carry Flag
        uint32_t        : 1;   // 保留位，未使用
        uint32_t ZF     : 1;   // Zero Flag
        uint32_t SF     : 1;   // Sign Flag
        uint32_t TF     : 1;   // Trap Flag
        uint32_t IF     : 1;   // Interrupt Enable Flag
        uint32_t DF     : 1;   // Direction Flag
        uint32_t OF     : 1;   // Overflow Flag
        uint32_t IOPL   : 2;   // I/O Privilege Level
        uint32_t NT     : 1;   // Nested Task Flag
        uint32_t        : 1;   // 保留位，未使用
        uint32_t RF     : 1;   // Resume Flag
        uint32_t VM     : 1;   // Virtual-8086 Mode
        uint16_t        : 14;  // 保留位，未使用
    };
    uint32_t val;              // 用于一次性访问所有标志的值
} eflags;
}CPU_state;


extern CPU_state cpu;

static inline int check_reg_index(int index) {
	assert(index >= 0 && index < 8);
	return index;
}

#define reg_l(index) (cpu.gpr[check_reg_index(index)]._32)
#define reg_w(index) (cpu.gpr[check_reg_index(index)]._16)
#define reg_b(index) (cpu.gpr[check_reg_index(index) & 0x3]._8[index >> 2])

extern const char* regsl[];
extern const char* regsw[];
extern const char* regsb[];

#endif
